Window fittings for actuating drive rods have been described in German patents DT-GM No. 7,025,066 published Mar. 11, 1971 and DT-OS No. 2,033,042 published Jan. 5, 1972. Additionally, a special extended form of such driving rod fittings are sold under the designation "SIEGENIA-TRIAL-GETRIEBE".
In these known drive rod fittings, the drive housing consists of two housing parts which are designed and assembled in such a manner that they meet each other in a plane corresponding to the plane of the center of rotation of the turnable member. At least in the areas supporting the turnable member and for the guidance of the drive rod, the two housing parts are symmetrical and mirror images.
To make sure that in such a drive housing design the forces which appear during the operation of the drive rod fitting can be controlled, it is not only necessary to tightly connect the two housing parts in the direction of the axis of rotation of the turnable member, but both housing parts must also be connected to the inverted track, so that the tilting forces which act on the housing may be safely intercepted. Such tilting forces arise, for instance, when the support rosetta for the service handle of the driving rod fitting (connected to the housing conventionally by anchor bolts) is forcibly tightened. At that time the drive housing does not engage with its side surfaces the parallel side surfaces of a recess formed in the casement wings of windows and doors. This is always the case when such a driving rod fitting must be inserted into windows and doors made of metal or plastic extrusions.
By directly fastening both housing parts of the drive-housing to the inverted track, the two housing halves are first connected with the driving housing during mounting after attachment of driving rod and the pinion. Only then may the drive housing be fastened to the inverted track. This fastening of the drive housing to the inverted track is done by a riveting operation because with a welding operation such as spot welding, the possibility exists that the movable driving members, enclosed within the drive housing, could back tightly onto the housing parts, as consequence of electrical shut-offs and not be turnable at all, or only with considerable difficulty.
German patent DT-GM No. 7,127,215 published on Sept. 30, 1971 teaches the use of a space for the drive housing of such drive rod fittings whereby the housing part can be welded before the mounting of the drive on the inverted track. The possibility of welding is attained at the cost of other disadvantages. For example, one important disadvantage is that the drive housing has to be put together from two housing parts in which the separating plane practically runs parallel to the inverted plane. In this design of the drive housing, the pinion is supported only in one housing part and the drive rod is guided only in the other housing part. Due to this design, the radial force-components, which appear during the transfer of motion between the pinion and the driving rod are not absorbed by the housing itself, but act on the connecting media of the housing, namely on the rivets or bolts.
Another disadvantage of the conventional drive design is that the pinion which serves as a driving member is not equipped with supports on which the housing may be supported. However, it is supported with its tooth circumference lying against a corresponding arcuate wall of one of the housing parts. In this method, considerable friction forces have to be overcome which makes the drive difficult to operate and, after a short working period, wear shows up caused by the friction of the pinion teeth on the support wall of the housing.
In this known design of drive housing for drive rod fittings a considerable reduction of the durability is accepted in favor of production simplification. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide window hardware which eliminates the above-mentioned deficiencies of the known design of drive housings for drive rod fittings, but at the same time makes use of their advantages.
Another object of this invention is the provision of a drive-rod fitting of the previously-described type in which one housing part of the drive housing can be tightly connected to the track before mounting, but in which, in spite of this, the reaction forces which act during the operation of the drive between the turnable member and the driving rod engaged to it are directly absorbed by the housing parts of the drive housing, so that the connection between the two housing parts is relieved from these reaction forces.
A further object of the present invention is the provision of window hardware in which rivet connections between the drive housing and the inverted track are avoided.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.